Then along comes Darwin 1831 1836 AP Biology

Then along comes Darwin… 1831 -1836 AP Biology 22 years old!

First to describe how evolution can occur. Descent with modification from natural selection explained 1. unity of life 2. diversity of life 3. relationship between organisms & their environment

natural selection = differential reproductive success random changes

Then along comes Darwin… & those dang finches! Descendant species Warbler finch Cactus finch Ancestral Woodpecker finch species Sharp-beaked finch Small insectivorous tree finch s fin ch e Medium ground finch s he Tr ee c fin Bud eater nd Insect eaters Seed eaters Vegetarian finch AP tree Biology ou Cactus eater Gr Large insectivorous tree finch Small ground finch r e l b r a W finch Large ground finch

Correlation of species to food source Seed eaters Flower eaters Insect eaters Rapid speciation: new species filling niches, because they inherited successful adaptations. AP Biology radiation Adaptive

adaptive radiation § genetic divergence from one to many species. Why? Ability to fill a niche. Use a resource, adapt to a new habitat, etc. § Competitive exclusion - only one species can fill the exact same niche for any length of time. Competition for the same resources will cause one to adapt to new conditions or be excluded AP Biology 64

Beak variation in Galapagos finches (a) Cactus eater. The long, sharp beak of the cactus ground finch (Geospiza scandens) helps it tear and eat cactus flowers and pulp. AP Biology (c) Seed eater. The large ground finch (Geospiza magnirostris) has a large beak adapted for cracking seeds that fall from plants to the ground. (b) Insect eater. The green warbler finch (Certhidea olivacea) uses its narrow, pointed beak to grasp insects.

EVIDENCE § Homology § Embryology § Fossil record § SIMILAR STRUCTURES FROM SPECIES THAT ARE EXTINCT (FOSSIL RECORDS) COMPARED TO MODERN SPECIES AP Biology 86

Glyptodont fossils Sloth fossils Modern sloth Modern armadillos AP Biology Why should extinct species & living species be found on the same continent?

§ The process of evolution drives the diversity and unity of life cells DNA AP Biology

1. What are the lines of evidence that support Darwin’s ideas? Fossil record 550 500 Body size (kg) 450 Equus 400 350 300 250 Merychippus 200 Mesohippus Hyracotherium 150 100 50 AP Biology Nannippus 60 55 50 45 40 35 30 25 20 Millions of years ago 15 10 5 0

2. What are the lines of evidence that support Darwin’s ideas? Terminal bud Lateral buds Cabbage Artificial selection Brussels sprouts Leaves Flower cluster Kale Cauliflower Stem Flower and stems Broccoli AP Biology Wild mustard Kohlrabi

ARTIFICIAL SELECTION § ONLY SPECIES WITH A FAVORED TRAIT ARE ALLOWED TO BREED AP Biology 13 12

Selective breeding the raw genetic material (variation) is hidden there Text AP Biology